Casting wheel with band positioning device



D. B. COFER 3,326,271

CASTING WHEEL. WITH BOND POSITIONING DEVICE June 20, 1967 Filed Aug. 4, 1966 INVENTOR DANIEL B COFER United States Patent 3,326,271 CASTING WHEEL WITH BAND POSITIONING DEVICE Daniel B. Cofer, Carrolltou, Ga., assignor to Southwire Company, Carroilton, Ga., a corporation of Georgia Filed Aug. 4, 1966, Ser. No. 570,306 8 Claims. (Cl. 164278) ABSTRACT OF THE DISCLOSURE What is disclosed herein is a casting machine having a casting wheel with a groove in a peripheral band engaging surface, a band which is positioned relative to the band engaging surface of the casting wheel so as to close a portion of the groove, and a band positioning device for positioning the hand against the band engaging surface of the casting wheel. The band positioning device includes both a 'band support wheel and a band deflecting means for deflecting the band toward the band engaging surface of the casting wheel as the band extends between the band supporting surface of the band support wheel and the band engaging surface of the casting wheel. The band is deflected by the band deflecting means from a substantially vertical path into a path which is inclined downwardly toward the band engaging surface of the casting wheel and which coincides with a chord of a circle defined by the ban-d engaging surface of the casting wheel. The band deflecting means is disclosed herein as including a pivotably and yieldably mounted band deflecting roller which is positioned between the band support wheel and the casting Wheel and which is small relative to both the band support wheel and the casting wheel.

This invention relates to casting machines and more particularly to a casting machine in which molten metal is solidified in a mold defined by a groove in the peripheral surface of a casting wheel and by a band which closes the groove.

An essential requirement of casting machines in which molten metal is solidified in a mold defined by a groove in the peripheral surface of a casting wheel and by a band which closes the groove is the proper positioning of the band relative to the peripheral surface of the casting wheel. This is because the band is an essential element in forming the mold and frequently supports most of the Weight of molten metal in the mold. Moreover, a band which is improperly positioned on a casting wheel will permit molten metal to escape between the band and the casting wheel to form fins on the resulting cast metal which must be subsequently removed.

A variety of band positioning devices for positioning a band relative to the peripheral surface of a casting wheel have been used in prior art casting machines to meet this requirement. These prior art band positioning devices have characteristically used various arrangements of one or more band support wheels to position the band relative to the peripheral surface of the casting wheel. However, regardless of the band support arrangement used, a difliculty with most prior art band positioning devices is that access to the entry end of the mold is limited by the path of the band as it approaches the peripheral surface of the casting wheel either because of the positions of the support wheels or because of the relatively large size of the support wheels. This limiting of access to the entry end of the mold has prevented the positioning of a tundish or other means for providing molten metal at the entry end of the mold in that plurality of positions required by various operating conditions.

Moreover, where band support wheels of relatively large size have been used in prior art band positioning ice devices, their weight has made them difficult to move relative to the peripheral surface of the casting wheel. This has caused relatively large amounts of power to be required for that movement of the support wheels necessary to maintain constant band tension. It has also caused these prior art band positioning devices to be relatively slow in responding to changes in band tension caused by changes in band temperature.

The invention disclosed herein overcomes these and other difliculties encountered in the prior art in that it provides a casting machine having a band positioning device which allows substantially unlimited access to the entry end of the mold for positioning a tundish or other means for providing molten metal at the entry end of the mold in that variety of positions required by various operating conditions. Moreover, the invention provides a casting machine having a band positioning device which maintains the band in position on the peripheral surface of the casting wheel with substantially constant band tension and without relatively large amounts of power being required for movement of the support wheels. In addition, the invention provides a casting machine having a band positioning device which is quickly responsive to changes in band tension.

These improvements in a casting machine are provided by a band positioning device which includes a band support wheel positioned adjacent the peripheral surface of the casting wheel for supporting the band, and a band deflecting means positioned between the band support wheel and the peripheral surface of the casting wheel for deflecting the band toward the peripheral surface of the casting wheel. The position and size of the band deflecting means provide a path for the band relative to the peripheral surface of the casting wheel which permits substantially unlimited access to the entry end of the mold for convenient positioning of a tundish or other means for providing molten metal at the entry end of the mold.

Moreover, the position of the band deflecting means provides control of band tension by motion of the band deflecting means only and the relatively small size of the band deflecting means permits that movement required for constant band tension to be quickly responsive to changes in band tension and to be made with a relatively small amount of power. In addition, in an embodiment of the invention in which the band deflecting means yieldably urges the band toward the peripheral surface of the casting wheel with a substantially constant force, the band deflecting means not only serves to maintain the band in position on the peripheral surface of the casting wheel with substantially constant band tension, but it also serves to yieldably provide for the passage of a foreign object between the band and the peripheral surface of the casting wheel without damage to either the band or the casting wheel.

These and other features and advantages of the invention will be more clearly understood from the following detailed description and the accompanying drawing in which:

The figure is a partially cut away front elevational view of the casting machine embodying the invention disclosed herein.

This figure and the following detailed description disclose a specific embodiment of the invention, but the invention is not limited to the details disclosed since it may be embodied in other equivalent forms.

The invention disclosed herein is best understood in terms of a casting machine C having a casting wheel 11 with a groove 12 in a peripheral band engaging surface 13. A portion of the groove 12 is closed by a band 14 so that the groove 12 and the band 14 define a mold M into which molten metal is poured through a spout S from a tundish or other means for providing molten metal at the entry end 16 of the mold M. The casting wheel 11 is rotatably mounted on a base member 17 and the band 14 is positioned relative to the band engaging surface 13 of the casting wheel 11 by .a plurality of band support Wheels 18, 19, and 20 which are also rotatably mounted on the base member 17.

Thus, the casting machine C is generally conventional in construction and operation and it is for this reason that all of the details of its construction .and operation need not be disclosed herein. However, in a casting machine C which embodies the invention disclosed herein, the band support wheel 18 adjacent the entry end 16 of the mold M is positioned a substantial distance from the band engaging surface 13, of the casting wheel 11 and a band deflecting means 21 is positioned between the casting wheel 11 and the band support wheel 18. The band deflecting means 21 serves to deflect the band 14 toward the band engaging surface 13 of the casting wheel 11 as the band 14 extends between the casting wheel 11 and the band support wheel 18.

It will be understood from the figure that in the absence of the band deflecting means 21 and with the length of the band 14 properly selected for the band 14 to be nevertheless held firmly against the band engaging surface 1343f the casting wheel 11 as it extends between the banid u port wheel 18 and the band support wheel 19, the band 14 would extend between the band engaging surface 13 of the casting wheel 11 and the peripheral band supporting surface 22 of the support wheel 18 in a substantially vertical path such as the path 23 indicated by the dashed line in the figure. The path 23 is tangential to both the band engaging surface 13 of the casting wheel 11 and the band supporting surface 22 of the band support wheel 18 and would result in the band 14 and the casting wheel 11 having positions relative to each other which would limit access to the mol M and positioning of the tundish 15.

Accordingly, it will also be understood that in deflecting the band 14 toward the casting wheel 11, the band deflecting means 21 serves to deflect the band 14 from a path 23 which would limit access to the mold M into a path 24. As can be seen from the figure, the path 24 is inclined downwardly from the band supporting surface 22 of the band support wheel 18 toward the band engaging surface 13 of the casting wheel 11 and coincides with the chord 25 of .a circle defined by the band engaging surface 13 of the casting wheel 11. The path 24 serves to provide substantially unlimited access to the mold M for positioning the tundish 1-5 or other means for providing molten metal at the entry end of the mold M.

However, the band deflecting means 21 not only deflects the band 14 into a path 24 which allows substantially unlimited access to the mold M, but when desired, it also provides for control of band tension in the band 14 simply by controlling the deflection'of the band 14. Moreover, the band deflecting means 21 provides control of band tension in the band 14 without requiring movement of a relatively large structure such as a support wheel 18, 19 or 20. This is because the band deflecting means 21 may be relatively small since it does not determine the path 26 of the band 14 between the band support wheel 18 and the band support wheel 20 and only partially determines the path 24 of the band 14 between the band support wheel 18 and the casting wheel 11. The absence of a required to move relatively large structure results in the band deflecting means 21 providing control of band tension without a substantial amount of power being necessary and in a manner which is quickly responsive to changes in band tension resulting from causes such as changes in band temperature.

This will be better understood by considering the specific band deflecting means 21 provided by that embodiment of the invention disclosed herein. In this embodiment of the invention, the band deflecting means 21 comprises a band deflecting roller 27 rotatably mounted and-when a conventional pressure release valve 34 is at one end of a lever member 28. The other end of the lever member 28 is operatively connected to a power means such as actuator unit 29 and the lever member 28 is pivotably positioned on the base member 17 by a pivot pin 30.

The actuator unit 29 is a conventional arrangement of a cylinder 31 and piston rod 32 in which fluid pressure supplied by line 33 from a fluid source (not shown) urges the piston rod 32 outwardly from the cylinder 31 and it will be understood from the figure that fluid pressure in the cylinder 31 causes the band deflecting roller 27 to pivot toward the band engaging surface 13 of the casting wheel 11. It will also be understood that the force with which the band 14 is urged toward the casting wheel 11 is dependent upon the fluid pressure within the cylinder 31 and may be increased or decreased simply by changing the fluid pressure within the cylinder 31 in conventional manner. Thus, if the length of the band 14 is selected so that the band deflecting roller 27 does not engage the casting wheel 11 as the band deflecting roller 27 urges the band 14 toward the casting wheel 11, constant band tension is maintained in the band 14 by the band deflecting means 21 simply by maintaining substantially constant fluid pressure within the cylinder 31.

fiir'ijfaddition, when the line 33 includes a check valve 36 provided the cylinder 31 for release of fluid from the hydraulic cylinder 31 into a fluid discharge line 35 if fluid pressure within the hydraulic cylinder 31 exceeds a predetermined value, the band engaging roller 27 will continuously and yieldably maintain substantially constant band tension in the band 14. This is because the force exerted on the band deflecting roller 27 by the band 14 with an increase in band tension serves to increase fluid pressure in the cylinder 31 above the predetermined value and will cause the release valve 34 to open and the lever member 28 to pivot in a clockwise direction as viewed in the figure until the force exerted by the band 14 decreases. Similarly, when the force exerted on the band deflecting roller 27 by the band 14 decreases with a decrease in band tension, the lever member 28 pivots in a counterclockwise direction as viewed in the figure until the force exerted by the band 14 increases and equals the force resulting from the fluid pressure in the cylinder 31 provided by line 33.

It will be understood that the actuator unit 29 is only one means of providing a continuous and yieldable band tensioning force and that regardless of the means used, the band deflecting means 21 disclosed herein requires a minimum of power and is quickly responsive because of the relatively small size of the band deflecting roller 27. Moreover, it will also be understood that where the band 14 is deflected toward the casting wheel 11 with a yieldable force, the band deflecting means 21 will quickly respond to the passage of a foreign object between the band 14 and the casting wheel 11 by pivotable motion of the lever member 28 and band deflecting roller 27 away from the casting wheel 11 so as to prevent damage to either the band 14 or the casting wheel 11 by the foreign object.

It will be obvious to those skilled in the art that many variations may be made in the embodiments chosen for the purpose of illustrating the present invention Without departing from the scope thereof as defined by the appended claims.

What is claimed as invention is:

1. In a casting machine, a band, a casting wheel having a peripheral band engaging surface in which is formed a groove having a portion of its length closed by said band, and a band positioning device including a band support wheel having a peripheral band supporting surface positioned to support said band as said band extends between said band supporting surface and said band engaging surface, and a band deflecting means for deflecting said band as said band extends between said band supporting surface and said band engaging surface toward said band engaging surface and from a substantially vertical path tangential to both said band supporting surface and said band engaging surface into a second path which is inclined downwardly from said band supporting surface toward said band engaging surface and which coincides with a chord of a circle defined by said band engaging surface, said band deflecting means including a band deflecting roller which contacts said band, which is small relative to said band support wheel, and which is pivotable about a pivot point downwardly displaced from said band deflecting roller.

2. The casting machine of claim 1 including a power means for yieldably urging said band deflecting roller against said band.

3. The casting machine of claim 2 in which said band deflecting roller is rotatably mounted on a lever member pivotable about said pivot point, in which said power means is operatively connected to said lever member, and in which said pivot point is between said band deflecting roller and said power means.

4. The casting machine of claim 3 in which said power means is operatively connected to said lever member with a rod extending from a cylinder.

5. The casting machine of claim 3 in which said power means is a means for pivoting said lever member about said pivot point by fluid pressure.

6. The casting machine of claim 5 in which said fluid pressure is substantially constant.

7. The casting machine of claim 1 in which a tundish is positioned between said casting wheel and said second path.

8. The casting machine of claim 7 in which a spout extends from said tundish into said groove between said casting wheel and said band deflecting roller.

References Cited UNITED STATES PATENTS 1,220,211 3/1917 Feldkamp et al 22 57.4 1,581,091 4/1926 Stewart 74 242.11 2,221,585 11/1940 Klein 6161 74 242.11 2,904,860 9/1959 116161611 22-574 2,928,148 3/1960 Porterfield 224-574 3,142,873 8/1964 1162616116161 22 57.4 3,187,674 6/1965 Hammelmann 74-2429 X FOREIGN PATENTS 1,035,900 4/1953 France.

I. SPENCER OVERHOLSER, Primary Examiner.

R. S. ANNEAR, Assistant Examiner. 

1. IN A CASTING MACHINE, A BAND, A CASTING WHEEL HAVING A PERIPHERAL BAND ENGAGING SURFACE IN WHICH IS FORMED A GROOVE HAVING A PORTION OF ITS LENGTH CLOSED BY SAID BAND, AND A BAND POSITIONING DEVICE INCLUDING A BAND SUPPORT WHEEL HAVING A PERIPHERAL BAND SUPPORTING SURFACE POSITIONED TO SUPPORT SAID BAND AS SAID BAND EXTENDS BETWEEN SAID BAND SUPPORTING SURFACE AND SAID BAND ENGAGING SURFACE, AND A BAND DEFLECTING MEANS FOR DEFLECTING SAID BAND AS SAID BAND EXTENDS BETWEEN SAID BAND SUPPORTING SURFACE AND SAID BAND ENGAGING SURFACE TOWARD SAID BAND ENGAGING SURFACE AND FROM A SUBSTANTIALLY VERTICAL PATH TANGENTIAL TO BOTH SAID BAND SUPPORTING SURFACE AND SAID BAND ENGAGING SURFACE INTO A SECOND PATH WHICH IS INCLINED DOWNWARDLY FROM SAID BAND SUPPORTING SURFACE TOWARD SAID BAND ENGAGING SURFACE AND WHICH COINCIDES 